The ratification by India, which follows that of the United States and China, the world's biggest greenhouse gas emitters, will help accelerate the enactment of the landmark Paris agreement on climate change forged last December.

"Now the time has come to ratify the COP21 protocol. India will do it on Gandhi Jayanti, on October 2," Modi said, referring to the anniversary of the birth of Gandhi, viewed by many as the father of modern India.

Modi said he chose Gandhi's birth anniversary as he gave an example of how to live with a low carbon footprint.

COP21 refers to the Conference of Parties protocol that commits both rich and poor nations to rein in rising carbon levels and aims to eliminate greenhouse gas emissions from human activity.

Modi was speaking at the Bharatiya Janata Party's national meeting in Kozhikode, in southern India's Kerala state.

In June, India indicated it would work towards joining the agreement on climate change this year. (Reporting by Malini Menon; Editing by Mark Potter)